Sea Vigil Water Quality Monitoring

NAsA - A r v g )ia a 2-^-3

The Humber Estuary : 1994

National Rivers Authority Anglian Region - Marine Section Peterborough NRA .Anglian Region February, 1996 Sea Vigil Water Quality Monitoring

The Humber Estuary

1994

National Rivers Authority Anglian Region Kingfisher House Orton Goldhay Peterborough. PE2 5ZR

Tel: 01733 - 371 811 Fax: 01733 - 231 840

ENVIRONMENT AGENCY

012068

© National Rivers Authority, February, 1996. A cknowledgements . Thanks are due to the crew of Sea Vigil, for their efforts in carrying out the survey work: Master of Sew Vigil, Captain Peter Sarjeant, B.Sc., Survey Officer, Tim Rhodes, B.Sc.,

This report was written and prepared by staff of the Anglian Marine Section: Dr. Chris Ashcroft, C.Chem., M.R.S.C., Ph.D., B.Sc.

T b c s m c a l N o r a :

Text composition is In Palatino 12/145 using Aldus PageMaker v 5 for Windows and output was to PostScript laser printer (HP LaserJet DID Postscript Plus). Graphs and tables were prepared taing Microsoft Excelv 5 for Window* and output was to PostScript colour Inkjet (HP DeskJet 1200c).

Map graphics were amended from Intergraph system files using Maplnfb v 3.0.2 (Text ootipusiUon In Classical Garamond).- The document was collated and photocopied In-house at FVtertxwcugh. [Final text version - hu_rpt2h-pcrf), 7* March '96] 'Sea Vigil' Humber Estuary Monitoring 1994

Contents

E xec u tiv e S u m m a r y ...... 3

B a c k g r o u n d ...... 5

D e s c r ip t io n o f t h e H u m b e r E st u a r y A r e a ...... 6 B a t h y m e tr y ...... 7

O b je c t iv e s ...... 7

W o r k P r o g r a m m e D e t a il s...... 8

P resentation o f R e su l t s...... 8

G en er a l C o m m e n t s ...... 9

J a n ua ry, 1 9 9 4 S u r v ey s...... 11

F ebr u a r y , 1 9 9 4 S u rv ey...... 11

M a rc h , 1 9 9 4 S u r v ey s...... 11

A p r il , 1 9 9 4 S u rvey...... 11

M ay, 1 9 9 4 S u rv ey...... 11

A u g u s t , 1 9 9 4 S u r v e y s...... 11

D e c e m b e r , 1 9 9 4 S u rv ey...... 1 1

E l e c t r o n ic D ata C o l l e c t io n ...... 1 2

C o n c l u sio n s...... 1 2

F u t u r e Y e a r s ...... 1 3

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E xec u tiv e. S um m ary

The NRA has an obligation to monitor and safeguard the coastal waters of England and Wales out to a designated 3 nautical mile limit. To meet this obligation, Anglian Region uses a purpose-designed coastal survey vessel, Sea Vigil, purchased in 1991. Data from surveys carried out within the Humber Estuary during 1994 are reported here. Their purpose was to gain information on the nutrient levels within one of the major estuaries in the U.K. During 1992 and 1993, Sea Vigil was involved in sampling for the MAFF/DoE JoNuS Project. From 1994, the NERC-funded LOIS Project was the major focus in the Humber Estuary with Sea Vigil involved in the sampling programme but not collecting inde pendent nutrient data. With Sea Vigil being based at Hull Marina during Humber Estuary survey programmes, the opportunity was taken to collect nutrient samples on other occasions, usually collecting surface samples at 11 sites between Hull and Haile Sand at the Estuary mouth. Samples were analysed on-board Sea Vigil for nitrate, ammonia, phosphate, silicate and nitrite, although the closure of the Anglian Region laboratory at the end of 1993 caused a disruption in operations. Field data were also collected. The Humber is a very turbid estuary with a strong tidal action, making it most unlikely that high levels of planktonic activity could occur and lead to events such as algal blooms. The main concern is likely to be how much nutrient load is exported to the North Sea, with the possible consequence of affecting the Lincolnshire Coast and the Wash. Nitrate and Phosphate concentrations only decreased slightly between Winter and Summer, whilst Silicate levels dropped by around 60% in the summer, suggesting that the only significant algal activity in the Humber Estuary is’consistent" with diatoms. There are five High Natural Dispersion Areas in the Humber Estuary, four of them within Anglian Region. Most of the data collected was within the associated 10 km zones. A limited monitoring programme continued until 1995. A review of all Regional coastal nutrient data would then be carried out, in order to define an appropriate monitoring programme, in line with the NRA's newly issued National Marine Monitoring Strategy.

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HUMBER ESTUARY

W ater Column Surveys

Sea Vigil, 1994.

B a c k g r o u n d . Following its formation in September, 1989, the National Rivers Authority has had an obligation to monitor and safeguard the coastal waters of England and Wales out to a designated 3 nautical mile limit. This responsibility was defined differently for the previous Water Authorities. Consequently, there was very little data collected for coastal water sites between the Humber and the Thames, the area covered by the Anglian Region of the NRA. The Coastal Survey Vessel of the Anglian Region of the NRA, Sea Vigil, has been collecting nutrient information from along the Anglian Coast since March 1992, using an on-board autoanalyser, permitting immediate analysis. Analytical techniques have been developed to measure the low levels of nutrients encountered in outer estuaries and coastal waters. This report is a summary of sampling carried out within the Humber Estuary during 1994. The data from surveys during 1992-1993 were reported previ ously. Separate reports over the Wash, the Lincolnshire Coast and the East Coast (outer Wash to outer Thames). Geographically, all of the Humber Estuary is within the defined 3-mile limit. However, it is clear from a number of sources that the influence of the Humber extends well outside the 3-mile limit. In the future, it may be necessary to sample further offshore, since there is evidence that the Humber plume returns inshore, hitting the south Lincolnshire Coast around the Skegness area. * The Humber Estuary Committee (HEC) has a substantial programme of monitoring throughout the Humber Estuary and produces an annual report on the data. There have also been two long term reviews produced (1961-1980 and 1981-1990). However, the majority of the water column monitoring is shoreline based. Within the Anglian part of the Estuary, no routine monitoring is carried out for all nutrients at these sites. The JoNuS Project (Joint Nutrient Study) focused on the Humber in 1992 and 1993. The NRA provided Sea Vigil to assist MAFF with extensive nutrient data collection within the Estuary. This JoNuS data was reported in the 1992-1993 report. The LOIS Project (Land Ocean Interaction Study) has since targeted the Humber Estuary, again with assistance from the NRA. The Project commenced in 1993 and uses airborne surveil lance in addition to water sampling. During LOIS surveys, however, the NRA did not collect or measure its own nutrient data, although data collected by LOIS scientists is available to the NRA. As a consequence, the only data collected by Sea Vigil from the Humber Estuary is of an opportunistic nature.

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As there is a lack of historical nutrient data, it is not yet possible to make comparisons and provide explanations. A continuing programme of nutrient monitoring was planned until 1995, in order to overcome these deficiencies. An overall report will be produced early in 1996, with the aim of putting the 1992-1995 data into geographic and historical perspective.

D e sc r ip t io n o f t h e H u m b e r E stu a r y A r ea . The Humber is an estuary extending for 62 km from the confluence of the Yorkshire Ouse and Trent river systems at Trent Falls to its mouth between Spurn Head on the North Bank and Donna Nook on the South Bank. It possesses the largest catchment of any UK estuary, covering an area of 24,240 km2, a fifth of the area of England. As the largest contributor of freshwater from the UK to the North Sea, the Humber has a special importance with regard to its quality. Much of the county's coal output, electricity generating capacity and manufacturing industry is concentrated within this catchment. Some 11 million people live within the catchment and on the banks of the Humber. Unlike many other UK estuaries, most of the population lives in inland cities, such as Birmingham, Leeds, Sheffield, Bradford, Leicester and Nottingham, and not in its immediate vicinity. The Humber is a valuable resource for the community in terms of fisheries and wildlife. Its immediate environs are predominantly rural with localised industrial areas. Two oil refineries, several chemical manufacturers and the ports of Grimsby, Hull and Immingham are all located along its banks. The Estuary is one of the UK's largest shipping complexes, handling both cargo and passengers. Additionally, there are vast areas of intertidal mudflats and sandbanks within the estuary, supporting large populations of overwintering wildfowl and waders, and are of international impor tance to eight bird species. As a consequence, a large majority of these areas have been designated as Sites of Special Scientific Interest (SSSI's) and Nature Reserves. The recreational use of the Humber is underdeveloped in comparison to other British estuaries. Sea angling, Wildfowling and other forms of outdoor recreation have been inhibited by problems of access and restricted provision of basic facilities, such as car parking. Cleethorpes is the only traditional seaside holiday resort within the Humber area, with a sandy bathing beach and associated tourist amenities. It has a designated EC Bathing Water. Some sailing also occurs on the estuary, although conditions are not ideal. The outer Humber supports a fin fishery and a shell fishery, although the fishing industry located in this area has declined during the second half of this century. The estuary remains important to North Sea fisheries because it is a nursery ground for flatfish. Under the DoE's revised definition of coastal waters, as applied for the Urban Waste Water Treatment Directive (UWWTD), the Humber Estuary downstream of the Hum ber Bridge was classified as coastal water, as opposed to estuary. This meant that 4 Anglian Region sewage discharges in the Humber Estuary were made candidate HNDA discharges, in addition to Hull, which is controlled by the adjacent Yorkshire Region. These discharges are Winteringham, Barton on Humber, Immingham and Pyewipe (Grimsby) and are marked in Figure la.

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The Humber is a highly energetic estuary with a characteristic turbid, swirling appear ance and a tidal range only exceeded in Britain by the west coasts of England. The tidal excursion of the Humber is several times greater than the displacement of seawater by freshwater input during the tidal cycle. This asymmetric tidal flow results in an extended residence period of effluents discharged, to .the estuary whilst they are - progressively diluted and edged towards the North Sea. The main inputs of polluting load to the Humber are from the freshwater rivers, which carry high effluent loads from Yorkshire and the industrial Midlands, as well as the direct discharges of sewage, particularly from Hull and Grimsby, and industrial effluents. There is a high level of nutrients within the Humber system, derived from these sewage and industrial sources. In 1993, the Humber was responsible for around one fifth of the UK's nitrogen and phosphorus inputs to the North Sea. However, there are currently no EQS values (Environmental Quality Standard) stipulated for nutrients within the Estuary.

Bathymetry The Humber Estuary is of classic shape, being about 8km wide at its mouth, narrowing to less than 500 metres in the Ouse and Trent. The maximum tidal range is 7m, which is only exceeded by the Bristol Channel within Britain. Current velocities can reach 11 km/hour (6.8 knots) at Spring tides. Whilst the sea is relatively shallow at the mouth along the southern side, there is a clearly defined deep water channel throughout the Estuary, although it does require dredging. The maximum charted depth is around 25m at the mouth, with the channel depth being less than 10m up as far as Hull and less than 5m above Hull. The channel shape changes regularly, especially above the Humber Bridge. It is the combination of these particular features that gives rise to complex tidal patterns and mixing of river water with estuary water. This is apparent from the results of these nutrient surveys.

O b je c t iv e s. The purpose of the 1994 surveys was to extend knowledge on nutrient levels and their variation throughout the coastal waters of the Anglia Region, particularly on a seasonal basis, building on the 1992-1993 data set. The EC Urban Waste Water Treatment and Nitrate Directives require information on nutrients, chlorophyll and water quality. Although Anglian Region currently does not have any coastal areas designated as "Sensitive Areas [Eutrophic]’‘ under the UWWTD, this work will provide data for any necessary reassessment. Following on from the JoNuS Project, valuable information could be collected on nutrient loads being discharged to the North Sea from the UK's largest contributor. The data can also help to assess the relevance of PARCOM load calculations, which by necessity, are measured well upstream at the freshwater limits of the tributary estuaries.

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Whilst no samples were collected during LOIS surveys, "opportunistic" sampling was undertaken at appropriate times when Sea Vigil was travelling to its Humber Estuary base at Hull Marina. The intention has been to collect data from all the coastal waters of the Anglian Region and produce a series of reports.

W o r k P r o g r a m m e D e ta ils. The intention of nutrient sampling in the Humber Estuary was to collect data that would produce a regression profile against salinity. There were 11 sites sampled between Hull Marina and Haile Sand at the mouth, with sites above Hull occasionally sampled. There were a few more extensive surveys undertaken, with additional sites. It is more effective for Sea Vigil to travel with the tide than against it and so surveys usually took place under a similar tidal state for a particular direction. The sample sites were defined at regular intervals on either side of the main channel, pilotage buoys being used as site markers. Some surveys were more intensive than others and different surveys would use a different set of sample points. ■ Previous data collected during 1992-1993 for the JoNuS Project demonstrated the complexity of the unmixed water masses in the Humber Estuary. Experiments were therefore made in carrying out transects across the Humber at a number of locations, in order to provide a clearer picture. Water was collected from the surface layer of the sea, at pre-defined sites, shown in Figure la, with site details in Table 1. Not all sites were sampled on each survey. Transects are shown in Figure lb. Field data was collected at the same time, including temperature, salinity and dissolved oxygen. Samples were immediately filtered and then put through the autoanalyser. The methods employed contained built-in Analyti cal Quality Control procedures and have satisfactorily passed special marine AQC exercises, particularly the stringent ones prepared for International Council for the Exploration of the Seas (ICES) exercises. Results were then sent to Peterborough for entering onto the laboratory database. During 1992 and 1993, the Anglian Region operated its own analytical laboratory. This was closed at the end of 1993. During 1994, there was no Marine Chemist available within the Region to control the nutrient analysis on-board Sea Vigil. Sometimes it was possible to borrow or hire a chemist from other NRA laboratories. Otherwise, samples had to be frozen and sent to an NRA laboratory (Fobney Mead, Llanelli or Nottingham). Due to the high turbidity of the Humber Estuary, it was not felt necessary to sample for chlorophyll.

P resentation o f R e s u l t s. The nutrient data reported here are from water column samples, filtered after collection through 0.45pm membrane filters and are therefore termed "dissolved nutrients". The nutrients are: nitrate, reactive phosphate, silicate, ammonia and nitrite. All results are

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in microgrammes per litre (pg.l1) and are given, by site, in Tables 4 to 13. Available field data are also given. In this summary, the term nitrate is used in preference to Total Oxidised Nitrogen (TON). There is an analytical distinction, TON being the summation of nitrate and nitrite results. Since the levels of nitrate are generally vastly higher than those of nitrite, - the distinction does hot significantly influence the data interpretation. The data is presented as a series of graphs, by survey (i.e. date). Table 3 lists the figure and table numbers. For each survey there is: • Table of Data; • Chart of Nutrient data against Salinity; • Chart of Dissolved Oxygen data against Salinity. It is traditional to represent estuary data as a regression against salinity for two reasons. Firstly, it will clearly show the pattern of dilution of river water with sea water, which, in a simple estuary with the river at the head (and no other inputs) would show a straight line of negative gradient for conservative parameters. A complex estuary like the Humber will haye additional peaks and troughs due to other inputs or changes in parameter behaviour, e.g. remobilisation of phosphate from sediments. The second reason is that by definition, the water in an estuary moves upstream as well as downstream. If the variability of any parameter is known in relation to salinity throughout the estuary, then a knowledge of the salinity regime at any point will be enough to deduce the necessary parameter values. To date, no allowance has been made for the variability in tidal state, nor an estimate of how critical it is to the interpretation of the data. This will require tidal cycle studies, at a variety of sites throughout the Estuary.

G eneral C o m m en ts. Nutrient, plankton and chlorophyll concentrations follow a seasonal pattern. During winter, there is negligible planktonic activity due to low light irradiance, with the majority of old biomass being regenerated into dissolved nutrients. Hence maximum nutrient concentrations are found in late Winter (January-February) Spring is the period for fastest planktonic growth and nutrient uptake. Consequently, chlorophyll concentrations are expected to be at their highest concentrations within the water column. This usually commences in Anglian Region in early March, through to May. Mid-summer is the period when dissolved nutrients first reach minimum concentra tions within the water column, having been consumed by the phytoplankton. The reason this does not coincide with high chlorophyll concentrations is because of grazing of phytoplankton by zooplankton. The nutrient levels are relatively high within the Humber Estuary, partly because it is an estuary as opposed to coastal water and also because of significant effluent inputs in the lower estuary.

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Nitrate is normally the most abundant of the nutrients. Nitrite is at low concentrations and rapidly oxidised to nitrate but can provide valuable information for nutrient processes. The surveys provide information in two forms: 1) Variations in spatial distribution of nutrient concentrations; 2) Variations in seasonal distribution of nutrient concentrations. There are a number of factors to be borne in mind when considering the data: • there are major fresh water nutrient inputs to the Humber Estuary, via the Trent and Ouse river systems; • there are other less significant fresh water inputs via the Hull and Ancholme rivers; • there are large sewage outfalls discharging to the Estuary at Hull, Immingham, Grimsby and Cleethorpes; Grimsby has a long outfall reaching to the deep water channel; • there are designated HNDA's at Hull, Winteringham, Barton, Hull, Immingham and Grimsby (Pyewipe); • there are numerous industrial discharges to the Estuary, particularly from the South Bank between Immingham and Grimsby; of these, Hydro Fertilisers, SCM Chemicals and Tioxide UK have locally significant nutrient loads; • the fast tidal currents and large tidal range should ensure good mixing; • high turbidity and strong tides usually inhibit photosynthetic activ ity, although the strong tides may create enough water turnover for sufficient light energy to be absorbed to facilitate a normal level of photosynthetic activity; • the deposition and resuspension of sedimentary material will influ ence the budgets of the dissolved nutrients; • in the middle estuary, the salinity range is great; at Blacktoft the extremes can vary between 0 arid 20 %o during the year; • the variable salinities will , lead to a biological species diversity throughout the estuary; • soluble nutrients are part of a very complex chemical equilibrium, involving phytoplankton, zooplankton and sediments. • the salinity of an estuary would be expected to range from less than 1 %o at low water at the freshwater end to close to 35 %> at high water at the seaward end; Further information is available from the annual HEC reports and the recent report 'The Quality of the Humber Estuary, 1980-1990' (NRA Water Quality Series Ho. 12).

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J anuary, 1 9 9 4 S u rv eys. There were 2 surveys carried out, one of the Middle Estuary between Lower Burcom and Chowder Ness, with results for 16 sites given in Table 4 and data presented in Figures 2 and 2a. The other was of the Lower Estuary from Hull Marina to Haile Sand with results for 11 sites given in Table 5 and data presented inFigures 3 arid 3a.

F ebruary, 1994 S urvey. Results are given in Table 6 with nutrient data presented in Figure 4, with 11 sites sampled from Haile Sand to Hull Marina. No dissolved oxygen data were collected.

M arch , 1 9 9 4 S u rv eys. There were 2 surveys carried out, one of the full Estuary between Blacktoft and Spurn, with results for 33 sites given in Table 7 and data presented in Figures 5 and 5a. The other was of the Lower Estuary from Hull Marina to Haile Sand with results for 11 sites given in Table 8 and data presented in Figures 6 and 6a.

A pr il, 1 9 9 4 S urvey. Results are given in Table 9 with data presented in Figure 7 and 7a, with 11 sites sampled from Haile Sand to Hull Marina.

M ay, 1 9 9 4 S urvey. Results are given in Table 10 with data presented in Figure 8 and 8a, with 33 sites sampled from Blacktoft to Spurn.

A u g u st, 1 9 9 4 S u rv eys. There were 2 surveys carried out, one of the full Estuary between Blacktoft and Spurn, with results for 33 sites given in Table 11 and data presented inFigures 9 and 9a. The other was of the Lower Estuary from Hull Marina to Haile Sand with results for 11 sites given in Table 12 and data presented in Figures 10 and 10a.

D ecem ber, 1 9 9 4 S urvey. Results are given in Table 13 with data presented in Figure 11 and 11a, with 28 sites on 14 transects siampled from Barrow Haven to Haile Sand. A map of sample locations is given in Figure lb.

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E l e c t r o n ic D ata C o l l e c t io n . On-board electronic sensors and towed arrays have been used to measure temperature, dissolved oxygen, salinity, turbidity, pH and chlorophyll in the Humber estuary, either on longitudinal profiles or cross-estuary transects. The longitudinal profiles, taking recordings every 10 seconds, collected data at about 40m intervals, whilst the transects had intervals of 2 seconds and about 5m respectively. Examples of these data are presented in Figures 12a to 12d for salinity, dissolved oxygen, temperature and turbidity. However, additional work is still required to confirm the values of this data as well as the validity of the techniques. Data show trends rather than absolute values.

C o n c l u s io n s . • It is clear that on a local basis, the Humber is not well mixed horizontally, across the Estuary. This is accentuated in the sampling programme which, by design, does not consistently sample from the main deep water channel. To do so, would lose data on this important aspect. In order to obtain a fuller picture of nutrient behaviour within the Humber system, horizontal profiles across the estuary are required. • The data presented reflects the known inputs of nutrients through out the Estuary, which include riverine, industrial and sewage effluents. • Ammonia concentrations occasionally rose at the seaward end, whilst other nutrients decreased; this was less emphasized than for data collected during 1992-93. • Unlike data for 1992-93, profiles did not contain spikes of increased phosphate concentration. • The maximum salinity of the Estuary as measured was always less than that of full seawater (nominally 35 %o). At Spurn Heaid,.maxi mum measured salinity was mostly in the range of 27%o to 30%o, reaching 33 %o in August. • Surveys that only went upstream as far as Hull (the NRA "opportun istic" surveys) measured the salinity minimum about 8%o in winter, rising to around 16%o in Spring and 23 %o in August. • Surveys that covered the anticipated full length of the estuary up to Trent Falls.at Apex or the Ouse at Blacktoft, did not reach freshwater salinities in the summer months, the minimum exceeding 5 %o. • The tidal state did not affect the nutrient-s alinity profiles, although the minimum and maximum salinities were not always sampled. The largest changes were either seasonal or as a result of possible inputs.

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Whilst there was only a small drop in Phosphate and Nitrate concen trations between Winter and Summer, Silicate concentrations fell by about 60% for the same period, suggesting that the only significant algal activity in the Humber Estuary is consistent with diatoms. There are a number of NRA sampling sites within each of the HNDA's. This should be helpful when the NRA has to make any judgements.

F utu re Y ea rs. The programme of monthly surveys in the Humber for LOIS is planned to continue but with no NRA nutrient sampling taking place. Opportunistic sampling will also continue during the Regional Work Programme, although the number of sites and their location will be reviewed. There is a large amount of data collected electronically, only some of which has been worked up. These will be reported on in due course. They consist of profiles of the Humber Estuary from minimum to maximum salinity as well as transects across the Humber at a number of locations. This includes the fluorescence determination of chlorophyll and turbidity. It may be necessary to sample further out than Spurn Head, even outside the three mile limit, in order to gain full information on the influence of the Humber Estuary on the coastal zone and the waters of the Lincolnshire Coast. It is also, hoped to investigate further the levels of phytoplankton, zooplankton, chlorophyll and turbidity. Future work should lead to an assessment of the influence of the Humber Estuary on the localised coastal waters. This report is one of a series covering the coastal waters of the Anglian Region of the NRA. The other reports are for the Lincolnshire Coast, the Wash and the East Coast (Norfolk, Suffolk & Essex). Further reports on Humber Estuary water quality data will be produced on an annual basis. An overall report will be produced early in 1996, with the aim of putting the 1992-1995 data into geographical and historical perspective and comparing the Humber Estuary with results from other estuaries. It will also permit a reassessment of the Coastal Monitoring Programme, in line with the NRA's National Marine Monitoring Strategy.

Water Column Surveys ‘Sea Vigil' 1994 Page 13

NRA - Anglian Region © HRA (A M S Graphic*) 1995

Figure la : Humber Estuary - 'Sea Vigil' Nutrient Sample Points NRA - Anglian Region © NRA (AMS Graphic*) 1995

Figure lb : Humber Estuary - 'Sea Vigil' Transect Lines HUM94_1C.XLS-Fig 2 Printed 14/02/96

Humber Estuary Nutrients 27th January 1994

3 . • COwm ©c E E < oT CQ jc a © -C

Salinity (%o)

10,000 T t 600

9.000 •TON (|jg/I - N) 'Silicate (pg/l - Si02) -- 500 8.000 Ammonia (pg/l - N)

■Phosphate (pg/l - P) O 7,000 %a. - 400 a .2 c 6>000 o 8 E S 5,000 - 300 E c*> < O + * O 4,000 CG a H & - - 200 © 3.000 -c flu

2.000 - - 100 1,000

0 _l_____I_____I_____L. _l______I______I______L J ____ I_____I____ L J _____I_____I____ !_ i______I______I______L. J _____I_____I------L. 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

Salinity (%o)

© NRA (AMS Gwphta) 1995 Figure: 6a NA ASGr 1995 M p ro G (AMS NRA © TON, Silicate (*ig/l) HUM94_1C.XLS-F ig 7 ig HUM94_1C.XLS-F 0.0 5.0 10.0 Humber Estuary Nutrients Estuary Humber 21st-22nd 1994 April 50 20.0 15.0 Salinity Salinity Figure :7 Figure (%o)

25.0 30.0 35.0 Printed 14/02/96 Printed

Phosphate, Ammonia (pg/1) HUM94_1C.XLS ■ Fig 7a Printed 14/02/96

21st- 22nd April 1994

Salinity (%«) ------

Humber Estuary Nutrients 4th May 1994

‘E o E E < 0>rs CS -C a & © -C

Salinity (%«)

HUM94_1C.XLS-Fig 9 Printed 14/02/%

Humber Estuary Nutrients 1st August 1994

K 2 c o £ £ < rs

£ cl o cu£

Salinity (%«)

Humber Estuary Dissolved Oxygen 1st August 1994 ...... i ...... —.... - — ...... ■ ■■

100

C 80 #o *z* a l. 70 -*•*5 08 £ 60 C V 50 DJD X C 40 V 30 O 6s 20 10

0 J _____ I_____I_____L J _____ I_____ I_____L J _____I_____L J _____I_____ I_____L. J _____I_____L_ J _____I_____I_____L J _____ I_____I_____L 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

Salinity (%o)

HUM94_1C.XLS-Fig 11 Humber Estuary Printed 14/02/96 North and South Bank Nutrients 9th December 1994

4J OC3 £ Z Ho

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 Salinity (%<>)

LOIS Humber Cruise SV12 Sea Vigil - 10th August 1994 Landward Leg - Flood Tide Selby ® Hull

Dissolved Oxygen - °/o Saturation -80 to 100 (0) ■60 to 80 (198) *40 to 60 (74) •20 to 40 (23) •10 to 20 (35) ■ 0 to 10 (31) NRA Anglian Region

^pin^Ha^Hmnber^sti^jy, l^th Augu^ 19^ -^Hssob^d Oxy^n on Flood Tide. NRA - Anglian Region © NRA (AMS Graphic*) 1995

LOIS Humber Cruise SV12 Sea Vigil - 10th August 1994 Seaward Leg - Ebb Tide

Selby ® Hull

Dissolved Oxygen - °/o Saturation •80 to 100 (0) •60 to 80 (177) •40 to 60 (89) •20 to 40 (68) •10 to 20 (26) • 0 to 10 (26) NRA Anglian Region Figure 12b : Humber Estuarv, 10th August, 1994 - Dissolved Oxygen on Ebb Tide. ss . A'' AA- s« A r a /V v

“4

FIX NO. 1020 1030 1040 1050 1150 1200 1210 1220 1230 OO HY 85 4 84.9 85.1 86 I 86.2 87.0 87.4 M i 37 9

Jf NL iii__r n JJ A. j i r

FIX NO. 1020 1030 1040 1050 1150 1200 1210 1221 1230 7.90 7.89 78 9 7.90 7.91 7.91 7.90 7J1 7.91

Figure 13a : LOIS HUMBER CRUISE SV14 Data logged to SEA VIGIL - 20th October 1994 Qubit Hull to Hawkin's Point - Ebb Tide TRAC V «» 1

18 y / V ^

FIX NO. 1610 1600 1550 1540 1530 1520 1510 1500 0 0 HY 84.0 84.9 86.0 85.6 86 7 87.2 87.4 89.4

r " —| * n p i * n A M |C- — ' 1 \ _ n J \____/TV l A _J» i —AJ\— . . . 1 — V i__ H

792

7 96

7.14

FIX NO 1610 1600 1550 1540 1530 1520 1510 1500 pH 7.96 7.94 7.95 7.94 7.94 7.95 7.95 7.98

Figure 13b : LOIS HUMBER CRUISE SV14 Data logged to SEA VIGIL - 20th October 1994 Qubit Hawkin's Point to Hull - Flood Tide TRAC V NRA - Anglian Region © ftRA (AMS Grapliia) 1996 NRA - Anglian Region © NRA (AMS Graph kj) 1996

North Hull © Ferriby

Barton

Immingham ®

Grimsby © Surface Dissolved Oxygen (% sat) YSI 59 logged to Qubit TRAC V Cleethorpes ® Bri88 — — * > 105 (63) ------*95 to 105 (277) — — * 9 0 to 95 (982) ------*85 to 90 (1032) x< 85 (416)

Fimire 14h : T ower Humber F.stuarv. 20th December. 1994 - Dissolved Oxveen. NRA - Anglian Region © NRA (AMS Grappa) 1996

Hull © North Ferriby ®

Barton

Immingham ®

Grimsby ® Surface Temperature (deg C) AML in 'Moonpool' logged to Qubit TRAC V Cleethorpes ® Bri& ------x6.8 to 7.2 (859) x6.4 to 6.8 (1164) ------*6.0 to 6.4 (633) ------*5.6 to 6.0 (105) ------x5.2 to 5.6 (8) NRA - Anglian Region © NRA (AMS Graphic*) 1996

Figure 14d : Lower Humber Estuary, 20th December, 1994 - Turbidity (uncalibrated)

HU_TAB2C.XLS-Table 1 1 Printed W 0 2 0 6

> A n g lia n S ite Nam e Easting Northing : Sample Point Name S&nijpte Point Code

H 2 484500 423500 HUMBER 0.1 KM O/S BLACKTOFT R03BIHU484423 485500 423500 HUMBER E .OUSE BEACON OFF FAXFLEET NESS R03BIHU485423

487500 423500 HUMBER W WALKER DYKE BEACON 1.3KM E APEX BUOY R03BIHU487423

489500 424500 HUMBER WHITTON CHANNEL OFF WHITTON R03BIHU489424

H 4 491500 425500 HUMBER 0.5 KM O/S WHITTON NESS R03BIHU491425

493500 425500 HUMBER BROUGH SAND OPPOSITE TIDE GAUGE R03BIHU493425

H 104 494500 424500 HUMBER 1.5 KM O/S WINTERINGHAM HAVEN R03B1H U494424

496500 424500 HUMBER CAPPER CHANNEL R03BIHU496424

498500 424500 HUMBER 0.8KM NE READS ISLAND R03BIHU498424

H 106 499500 424500 HUMBER 1.1 KM O/S CHOWDER NESS R03BIHU499424

499500 425500 HUMBER 0.8KM SW OF CHOWDER NESS R03BIHU499425

502500 424500 HUMBER NO.23 FLOAT 0.3KM E OF HUMBER BRIDGE R03BIHU502424

H 5 504500 425500 HUMBER NEAR HESSLE SAND 0.5 KM O/S R03BIHU504425 506500 426500 HUMBER NO.28 BUOY 2.6KM NE HESSLE SAND R03BIHU506426

H 107 508500 426500 HUMBER BUOY 26A 0.5 KM O/S WEST HULL R03BIHU508426 HUMBER BUOY 26 0.5 KM O/S HULL MARINA R03BIHU510427 H 26 / H 108 510500 427500 I 511500 428500 HUMBER NO.24 BUOY HULL ROAD R03BIHU511428

H21/H110 513500 427500 HUMBER BUOY 21 HEBBLES 0.4 KM O/S HULL R03BIHU513427

H 20 514500 427500 HUMBER BUOY 20 0.3 KM EAST OF BUOY 21 R03BIHU514427

H7/H16 515500 425500 HUMBER BUOY 16 SAND END 2.1 KM O/S R03BIHU515425

H 112 515500 426500 HUMBER BUOY 18 ELBOW 1.1 KM O/S R03BIHU515426

Anglian Site Name Easting Northing. Sample Point Name Sample Point Code

H 113 516500 423500 HUMBER BUOY 14 SKITTER HAVEN 1.7 KM O/S R03BIHU516423

516500 425500 HUMBER BUOY 16 SAND END 2.1KM O/S R03BIHU516425

H 17 517500 422500 HUMBER BUOY 17 NORTH HOLME 2.0 KM O/S R03BIHU517422

H 115 518500 419500 HUMBER BUOY 15 HOLME NOOK 1.2 KM O/S R03BIHU518419

H 11a 520500 417500 HUMBER BUOY 11A 1.3 KM O/S IMMINGHAM R03BIHU520417

H 116 521500 417500 HUMBER BUOY 11 HOLME 1.2 KM O/S IMMING. R03BIHU521417

H 10a 522500 415500 HUMBER BUOY 10A 1.1 KM O/S STALLINGBORO R03BIHU522415

H 117 522500 416500 HUMBER BUOY 9A 1.5 KM O/S IMMINGHAM R03BIHU522416

H 119 524500 415500 HUMBER BUOY 10 UPPER BURCOM 1.7 KM O/S R03BIHU524415

H 6b/H120 526500 414500 HUMBER BUOY 6B 3.0 KM O/S PYEWIPE R03BIHU526414 H 136 528500 413500 HUMBER BUOY 6A 2.1 KM O/S GRIMSBY R03BIHU528413

H6/H121 530500 412500 HUMBER BUOY 6 LOWER BURCOM 2.2 KM O/S R03BIHU530412 H 122 532500 411500 HUMBER BUOY 4B 3.1 KM O/S CLEETHORPES R03BIHU532411

H 4a/ H 123 534500 411500 HUMBER BUOY 4A CLEE NESS 4.4 KM O/S R03BIHU534411

H 13 536500 410500 HUMBER BUOY 4 BULL CHANNEL 5.3 KM O/S R03BIHU536410

H 2c 537500 406500 HUMBER BUOY 2C HAILE ANCHOR. 3.5 KM O/S R03BIHU537406

H 124 538500 409500 HUMBER BUOY BULL 1.4 KM O/S SPURN R03BIH U538409

H 2b 542500 405500 HUMBER BUOY 2B 6.8 KM O/S HAILE SAND R03BIHU542405

Direction of No* of Survey Date Survey Area Ran Samples

27-Januaiy-94 Humber Profile Up-stream 16 29-January-94 Humber Estuary Down-stream 11 17-February-94 Humber Estuary Up-stream 11 10-March-94 Humber Profile Down-stream 33 25-March-94 Humber Estuary Down-stream 11 21-April-94 Humber Estuaiy Up-stream 3 22-April-94 8 04-May-94 Humber Profile Down-stream 33 01-August-94 Humber Profile Down-stream 33 16-August-94 Humber Estuary Down-stream 11 09-December-94 Humber Transects Down-stream 28 .

Table 2 : Humber Nutrient Surveys • nra (AMS G^> ,995 from Sea Vigil Sample Sites HU_TAB2D.XLS - Table 3 Printed 07/0336

Dissolved Survey Date , Survey Area Data Table Nutrients Profile Oxygen Profile

27-Januaiy-94 Humber Profile Table 4 Figure 2 Figure 2a 29-J anuary-94 Humber Estuary Table 5 Figure 3 Figure 3a 17-Februaiy-94 Humber Estuaiy Table 6 Figure 4 No Data 10-March-94 Humber Profile Table 7 Figure 5 Figure 5a 25-March-94 Humber Estuaiy Table 8 Figure 6 Figure 6a 21-April-94 Humber Estuaiy Table 9 Figure 7 Figure 7a 22-April-94 04-May-94 Humber Profile Table 10 Figure 8 Figure 8a 01-August-94 Humber Profile Table 11 Figure 9 Figure 9a 16-August-94 Humber Estuaiy Table 12 Figure 10 Figure 10a 09-December-94 Humber - 14 Transects Table 13 Figure 11 Figure 11a

> Parameter Survey Date Survey Area Tidal State Profiled Figure No.

10-August-94 Upper Humber Estuary Flood Tide Dissolved Oxygen Figure 12a Ebb Tide Dissolved Oxygen Figure 12b Salinity, 20-October-94 Middle & Lower Ebb Tide Figure 13a Temperature. Humber Estuary Flood Tide DO & pH Figure 13b 20-December-94 Middle. Lower Ebb & Flood Tide Salinity Figure 14a & Outer Ebb & Flood Tide Dissolved Oxygen Figure 14b Humber Estuaiy Ebb & Flood Tide Temperature Figure 14c Ebb & Flood Tide Turbidity Figure 14d

Table 3 : Humber Surveys o mra cams 1995 Summary of Data Tables and Figures HU_TAB2C.XLS-Table 4 Printed 14/02/96

Field Water Silicate Chloro Temp DO DO Ammoni* TON Phosphate Nitrite Date and Tlnle Site No. > Site Name Salinity Depth Oigrt phyll ? ’ V VC) <%sat) (mg/l) (Mg/I N)

Water Silicate Chloro Temp 0 0 DO Ammonia TON Phosphate Nitrite Date and Time Site No. Site Name Salinity Depth pH (pgrt phyll r (°C> <%sftt) (mgfl) 0*8»N )

Field Water Silicate Chloro Temp DO DO Ammonia TON Phosphate Nitrite Date and Time Site No. ^ . Site Name . Salinity Depth W l phyil ♦ k (X) <%5&t) (mg/I) OigrtN) m

« mw (ams ,995 Table 6 : Humber Estuary Survey, 17th February 1994 i HU_TAB2C.XLS-Table 7 Printed 14/02/96

Field Water Silicate Chloro Temp DO DO Ammonia '.TON. Phosphate Nitrite Date wd Time Site No, SlteName Salinity Depth pH phvll rc , (%sat) (mg/I) (Mg/IN) W i N) j (p(5rt) 10-March 06:52 H 2 Blacktoft 0.65 7.31 5.6 83.4 9.98 308.0 6030 6600 124.0 2.0 10-March 06:59 Faxfleet Ness 0.72 7.33 7.4 83.2 9.94 287.0 6340 6710 126.0 4.3 10-March 07:07 Walker Dyke 0.78 7.44 6.6 81.0 9.66 271.0 6690 6970 141.0 4.7 10-March 07:15 Whitton Channel 0.94 7.40 6.4 80.7 9.61 245.0 6590 6950 125.0 2.7 10-March 07:22 H 4 Whitton Ness 1.15 7.35 5.9 80.9 9,65 236.0 6620 6820 127.0 3.7 10-March 07:29 Brough Island 1.81 7.15 5.9 82.1 9.79 215.0 6490 6680 124.0 3.5 10-March 07:35 H 104 Wintertngham Haven 2.56 7.14 5.2 80.8 9.60 182.0 6580 6610 117.0 2.8 10-March 07:44 Capper Channel 3.30 7.04 9.3 80.5 9.54 148.0 6610 6480 109.0 6.9 10-March 07:51 Reads Island 3.65 7.00 6.1 80.5 9.52 159.0 6380 6450 111.0 6.0 10-March 07:59 H 106 Chowder Ness 5.18 6.86 6.8 79.5 9.34 126.0 6260 6200 101.0 3.7 10-March 08:11 No 23 Float 6.93 6.60 8.3 81.1 9.46 103.0 6060 5740 96.4 5.0 10-March 08:19 H 5 Hessle Sand 7.65 6.54 4.3 80.5 9.38 80.4 6020 5660 93.5 5.8 10-March 08:27 Buoy 28 8.26 6.47 7.5 81.4 9.47 82.6 5860 5160 96.0 10.8 10-March 08:33 H 107 West Hull 7.92 6.48 9.0 81.6 9.46 84.6 5840 5650 94.7 8.7 10-March 08:42 H 26 / 108 Hull Marina 7.84 6.53 9.1 81.2 9.47 92.5 5730 5640 94.7 11.2 10-March 08:49 Hull Road 7.60 6.57 10.3 81.1 9.39 92.8 5790 5680 95.0 5.4 10-March 08:56 H 21 / 110 Hebbles 9.22 6.46 13.7 81.5 9.40 85.8 5400 5350 90.0 3.3 10-March 09:04 H 112 Elbow 10.66 6.34 10.7 81.7 9.37 74.2 5330 5140 84.7 4.0 10-March 09:09 Sand End 12.39 6.21 10.2 81.5 9.27 68.9 5010 4910 83.2 5.1 10-March 09:14 H 113 Skitter Haven 12.77 6.15 10.1 82.8 9.37 66.2 4800 4590 78.9 6.0 10-March 09:21 H 17 North Holme 11.78 6.25 8.8 82.1 9.27 74.3 5020 4920 80.9 6.2 10-March 09:30 H 115 Holme Nook 14.31 6.07 8.6 83.0 9.41 60.4 4610 4400 76.4 6.1 10-March 09:40 H 11a 1.3km Immingham 14.91 ! 6.06 10.6 83.8 9.38 61.0 4490 4240 74.2 6.6 10-March 09:46 H 116 1.2km Immingham 1,7.01 ■ 5.91 19.6 84.1 9.36 58.4 4080 3850 69.4 9.3 10-March 09:55 H 117 1.5km Immingham 17.18 ■ 5.90 16.9 83.9 9.34 55.3 4180 3890 67.9 5.2 10-March 10:02 H 119 Upper Burcom 17.68 ; 5.87 15.6 84.4 9.36 54.6 3970 3740 65.5 8.5 10-March 10:13 H 6b / 120 Pyewipe 18.55 5.81 11.7 85.8 9.48 54.3 3790 3520 63.2 7.5 10-March 10:24 H 136 Grimsby 20.68 5.74 10.5 86.9 9.51 53.4 3350 3160 58.2 4.5 10-March 10:33 H 6 / 121 Lower Burcom 21.91 5.73 8.8 88.0 9.51 48.8 3090 2960 54.0 2.9 10-March 10:42 H 122 Cleethorpes 22.45 5.71 10.3 88.2 9.47 47.8 2940 2840 53.6 4.5 10-March 10:50 H 4a / 123 Clee Ness 23.39 5.69 10.1 89.2 9.55 46.7 2720 2620 49.2 6.8 10-March 11:00 H 13 Bull Channel 24.81 ;5.69 13.5 89.6 9.50 45.8 2430 2320 43.6 4.9 10-March 11:10 H 124 Spurn 26.88 5.65 13.7 90.7 9.53 37.1 1960 1910 41.8 4.1 Table 7 : Humber Profile Survey, 10th March 1994 HU_TAB2C.XLS-Tebto 8 1 Printed 14/02/96

■ : s|: • FfeW Water m cate Chloro Tenip DO DO Ammonia TON Piittphate Nitrite Date and Time Site No. Site Name Salinity Depth pH (Mg* phyll <°C> (% siA) (mgrt) 0*g3 N) (pgAN) (pgflP) (pg/IN) <%*)

Field Water Silicate Chloro Temp DO DO Ammonia TON Phosphate Nitrite Date and Time . Site No. Site Name Salinity Depth pH W* phyll ♦ * * fC ) (% sat) (mg/I) (MgflN) Oig/IN) Oig/ir> (Mg/l N) (*•> (m) •> Sic*) (HfA> 21-April 23:19 H 2b Halle Sand 29.87 7.42 12.07.97 96.7 73.4 839 513 29.5 21-April 23:37 H 2c Haile Anchor 29.18 7.27 11.57.95 95.8 48.9 1990 1120 62.9 21-April 23:59 H 4a / 123 Clee Ness 28.13 7.31 9.57.89 94.3 49.5 2254 1180 1 55.5 22-April 00:15 H 6/ 121 Lower Burcom , 27.73 7.43 8.07.87 93.7 56.6 2380 1260 ; 58.0 22-April 00:32 H 6b / 120 Pyewipe 25.40; 7.36 15.37.87 92.8 58.2 2670 1420 ; 65.3 22-April 00:47 H 10a Stallingborough : 22.02 7.44 16.3 7.84 90.7 56.3 3120 1590 i 77.3 22-April 00:59 H 11a 1.3km Immingham 22.22 i 7.53 10.1 7.83 90.0 68.1 3250 1600 78.4 22-April 01:15 H17 North Holme 18.95: 7.65 11.1 7.81 87.8 54.3 3780 1750 ; 99.5 22-April 01:28 H 7 / 16 Sand End 16.15 7.72 9.2 7.81 86.1 57.7 3770 1960 I 106.0 i 22-April 01:38 H 20 Buoy 20 15.84 7.78 6.2 7.79 84.9 I 22-April 01:52 H 26 / 108 Hull Marina 1 10.45 8.08 10.6 7.80 81.6 1 i . i

I I H U _ M B 2 C .X L S - Table 10 Printed 14/02/96

. . ' field Water Silicate Chloro Teiiip DO , DO Ammonia TON Phosphate Nitrite pate andTinie Site No. Site Name Salinity Depth pH phyll CO (%$at) (mg/I) Qig/*N) Oig/IN) (Mg SiOa) nn (M?fl) 04-May 15:08 H 2 Blacktoft 5.20 13.08 5.4 7.93 84.6 32.9 5680 2080 117.0 04-May 15:17 Faxfleet Ness 5.10 13.08 6.8 7.93 84.9 30.7 6220 2100 114.0 8.0 04-May 15:26 Walker Dyke 6.63 12.98 7.1 7.89 84.9 6.8 04-May 15:34 Whitton Channel 6.82 12.93 6.4 7.89 84.5 5.6 04-May 15:43 H 4 Whitton Ness 8.00 12.81 5.5 7.86 84.1 23.6 5790 2070 112.0 4.6 04-May 15:51 Brough Island 8.41 12.84 5.4 7.86 84.6 24.3 5690 2150 106.0 6.3 04-May 15:58 H 104 Winteringham Haven 9.43 12.75 4.6 7.83 83.4 24.3 5670 2150 109.0 1.1 04-May 16:07 Capper Channel 9.64 12.86 8.6 7.85 85.3 29,2 5410 2110 105.0 04-May 16:14 Reads Island 11.31 12.74 6.7 7.84 85.6 25.3 5370 2130 108.0 04-May 16:22 H 106 Chowder Ness 13.68 12.43 6.3 7.78 83.7 40.7 5110 2080 106.0 04-May 16:34 No 23 Float 14.08 12.49 8.6 7.79 83.8 30.1 4870 2060 101.0 0.9 04-May 16:43 H 5 Hessle Sand 14.39 12.41 5.1 7.80 84.7 27.2 4520 1900 97.3 1.5 04-May 16:53 Buoy 28 15.90 12.27 7.5 7.78 83.3 26.5 4380 1870 97.5 2.2 04-May 17:01 H 107 West Hull . 9.3 33.7 4170 1810 , 94.6 1.5 04-May 17:10 H 26 / 108 Hull Marina . 15.86 12.26 9.9 7.78 83.7 32.4 4050 1800 94.1 1.3 04-May 17:17 Hull Road 16.13 12.24 11.67.79 84.1 33.9 4000 1780 ; 93.5 1.1 04-May 17:25 H 21 / 110 Hebbles 17.58 12.04 7.8 7.78 85.0 51.2 3880 1730 >92.5 2.2 04-May 17:35 H 112 Elbow . 18.85 11.86 10.1 7.76 85.5 36.4 3680 1670 89.5 1.4 04-May 17:41 Sand End 19.22 11.91 10.7 7.77 86.3 26.5 3413 1550 83.5 1.2 04-May 17:47 H 113 Skitter Haven 18.98 11.93 10.5 7.77 86.0 26.3 3330 1580 82.3 2.6 04-May 17:56 H 17 North Holme 19.60 11.86 9.6 7.77 86.2 28.5 3330 1550 81.6 1.4 04-May 18:07 H 115 Holme Nook 20.79 11,69 9.67.77 86.5 29.3 3250 1500 80.6 2.9 04-May 18:17 H 11a 1.3km Immingham 21.22 11.63 12.8 7.78 87.1 27.7 3040 1360 75.9 1.0 04-May 18:24 H 116 1.2km Immingham 21.89 11.55 20.1 7.78 87.4 30.0 2900 1340 72.8 04-May 18:32 H 10a Stallingborough 22.94 11.44 18.1 7.77 88.0 35.2 2750 1220 71.0 2.5 04-May 18:40 H 119 Upper Burcom 23.16 11.43 16.3 7.78 88.8 39.7 2480 1210 61.7 1.3 04-May 18:51 H 6b / 120 Pyewipe 24.59 11.34 12.1 7.81 91.0 31.5 2390 1070 60.3 0.6 04-May 19:03 H 136 Grimsby 24.97 11.27 11.1 7.82 91.1 . 38.4 2170 990 55.4 0.6 04-May 19:14 H 6 / 121 Lower Burcom 24.91 11.27 9.2 7.83 91.0 51.5 1960 1070 49.8 0.9 04-May 19:23 H 122 Cleethorpes 25.29 11.24 13.67.84 91.8 29.0 2130 1050 55.4 0.9 04-May 19:32 H 4a / 123 Clee Ness 25.90 11.14 9.8 7.83 92.2 37.9 1990 967 52.0 1.0 04-May 19:42 H 13 Bull Channel 26.40 11.11 13.5 7.85 92.6 36.2 1840 940 28.9 04-May 19:55 H 124 Spurn 27.19 10.95 11.7 7.88 93.4 33.5 1730 846 40.6

Field Water Silicate Chloro Temp DO DO Ammonia TON Phosphate Nitrite Date and Time Site No. Site Name Salinity Depth pH (Mtfl phyll < N (%*) (°C)

• • \ s % Field Water Silicate Chloro Temp DO DO Ammonia TON Phosphate Nitrite Date and Time Site No. . Site Name . Salinity Depth pH

omra(amsg^ „ 9 9 5 Table 12 : Humber Estuary Survey, 16th August 1994 HU_TAB2C.XLS - Table 13 Printed 14/02/96

Field Water Silicate Chloro Temp DO DO Ammonia TON Htosphate Nitrite Date and Time Site No.. Site Name Salinity Depth pH (Mg'* phyll ;<*C) (%sat) (m) SiO*)

o nRA (ams Grepi*.) ,995 Table 13 : Humber Transect Survey, 9th December 1994